Brigadier General James Monroe Williams

The Nile as seen from a cruise boat between Luxor and Aswan in Egypt

This is a list of the longest rivers on Earth. It includes river systems over 1,000 kilometres (620 mi) in length.

Definition of length

There are many factors, such as the identification of the source,[1] the identification or the definition of the mouth, and the scale of measurement[2] of the river length between source and mouth, that determine the precise meaning of "river length". As a result, the length measurements of many rivers are only approximations (see also coastline paradox). In particular, there seems to exist disagreement as to whether the Nile[3] or the Amazon[4] is the world's longest river. The Nile has traditionally been considered longer, but in 2007 and 2008 some scientists claimed that the Amazon is longer[5][6][7] by measuring the river plus the adjacent Pará estuary and the longest connecting tidal canal.[8] A peer-reviewed article published 2009 in the International Journal of Digital Earth concludes that the Nile is longer.[9]

Even when detailed maps are available, the length measurement is not always clear. A river may have multiple channels, or anabranches. The length may depend on whether the center or the edge of the river is measured. It may not be clear how to measure the length through a lake or reservoir. Seasonal and annual changes may alter both rivers and lakes. Other factors that can change the length of a river include cycles of erosion and flooding, dams, levees, and channelization. In addition, the length of meanders can change significantly over time due to natural or artificial cutoffs, when a new channel cuts across a narrow strip of land, bypassing a large river bend. For example, due to 18 cutoffs created between 1766 and 1885, the length of the Mississippi River from Cairo, Illinois, to New Orleans, Louisiana, was reduced by 351 kilometres (218 miles).[10]

These points make it difficult, if not impossible, to get an accurate measurement of the length of a river. The varying accuracy and precision also makes it difficult to make length comparisons between different rivers without a degree of uncertainty.

List of river systems longer than 1,000 km

For most rivers, different sources provide conflicting information on the length of a river system. The information in different sources is between parentheses.

Legend of colors used in main table, by continent
Continent color key
Africa Asia Australia Europe North America South America

Notes

  • When the length of a river is followed by an asterisk, it is an average of multiple information sources. If the difference in lengths between given information sources is significant, all lengths are listed. But if the lengths from secondary information sources are similar, they are averaged and that figure has an asterisk.
  • Scientists debate whether the Amazon or the Nile is the longest river in the world. Traditionally, the Nile is considered longer, but recent information suggests that the Amazon may be longer. Differences in the recorded length of the Amazon mainly depend on whether the course south of the Ilha de Marajó at the Amazon's mouth is to be treated as part of the Amazon, or as part of the separate Tocantins River. New evidence, (dated 16 June 2007) obtained from a high-altitude scientific venture in the Andes, claims that "the Amazon is longer than the Nile by 100 km, with its longest headwater being the Carhuasanta stream originating in the south of Peru on the Nevado Mismi mountain's northern slopes and flowing into the Río Apurímac".[33] However, the origin of the river at Nevado Mismi had already been known more than one decade earlier (see Jacek Palkiewicz), and satellite based measuring from this origin to the Amazon mouth has resulted in not more than 6,400 km.
  • Generally, the most commonly used/anglicised name of the river is used. The name in a native language or alternate spelling may be shown.
The Mississippi River just north of St. Louis
Saint Lawrence River along the New York-Quebec border

River systems that may have existed in the past

Amazon–Congo

The Amazon basin formerly drained westwards into the Pacific Ocean, until the Andes rose and reversed the drainage.[34]

The Congo basin is completely surrounded by high land, except for its long narrow exit valley past Kinshasa, including waterfalls around Manyanga. That gives the impression that most of the Congo basin was formerly on a much higher land level and that the Congo River was rejuvenated by much of its lower course being removed, likeliest when Africa split from South America when Gondwanaland broke up due to continental drift, and before that, the Congo would likely have flowed into the Amazon,[34] producing a river around 6000 miles or 10,000 km long.

West Siberian Glacial Lake drainage

This river would have been about 10,000 km (6,200 mi) long, in the last ice age. Its longest headwater was the Selenga river of Mongolia: it drained through ice-dammed lakes and the Aral Sea and the Caspian Sea to the Black Sea.

Lobourg

During the last glacial maximum, much of what is now the southern part of the North Sea was land, known to archaeologists as Doggerland. At this time, the Thames, the Meuse, the Scheldt, and the Rhine probably joined before flowing into the sea, in a system known by palaeogeographers as the Loubourg or Lobourg River System.[35] There is some debate as to whether this river would have flowed southwest into what is now the English Channel, or flowed north, emerging into the North Sea close to modern Yorkshire. If the latter hypothesis is true, the Rhine would have attained a length of close to 1,650 kilometres (1,030 mi). The former hypothesis would have produced a shorter river, some 1,400 kilometres (870 mi) in length. Current scientific research favours the former opinion, with the Thames and Rhine meeting in a large lake, the outflow of which was close to the present-day Straits of Dover.[36]

See also

Notes and references

Notes
  1. ^ a b The Nile is usually said to be the longest river in the world, with a length of about 6,650 km,[3] and the Amazon the second longest, with a length of at least 6,400 km.[4] In 2007 and 2008, some scientists claimed that the Amazon has a length of 6,992 km and was longer than the Nile, whose length was calculated as 6,853 km.[6][11][7] They achieved this result by adding the waterway from the Amazon's southern outlet through tidal canals and the Pará estuary of the Tocantins.[citation needed] The dispute is: "Is the channel south of Isla de Marajó to be treated as part of the Amazon, or as part of the Rio Tocantins?"[citation needed] A peer-reviewed article, published in 2009, states a length of 7,088 km for the Nile and 6,575 km for the Amazon, measured by using a combination of satellite image analysis and field investigations to the source regions.[9] According to the Encyclopædia Britannica, as of 2020, the length of the Amazon remains open to interpretation and continued debate.[4][8] Note that disputed values have been put in parentheses.
References
  1. ^ "Where Does the Amazon River Begin?". National Geographic News. 2014-02-15. Archived from the original on February 15, 2014. Retrieved 2018-12-25.
  2. ^ for more on this, see coastline paradox
  3. ^ a b c d "Nile River". Encyclopædia Britannica. 2020. Archived from the original on 10 October 2017. Retrieved 8 December 2020.
  4. ^ a b c d e f "Amazon River". Encyclopædia Britannica. 2020. Archived from the original on 8 November 2020. Retrieved 8 December 2020.
  5. ^ Amazon Longer Than Nile River, Scientists Say Archived 15 August 2012 at the Wayback Machine
  6. ^ a b "Amazon river 'longer than Nile'". BBC News. 16 June 2007. Archived from the original on 26 September 2010. Retrieved 3 August 2010.
  7. ^ a b "Studies from INPE indicate that the Amazon River is 140km longer than the Nile". Brazilian National Institute for Space Research. Archived from the original on 11 April 2011. Retrieved 3 August 2010.
  8. ^ a b "How Long Is the Amazon River?". Encyclopedia Britannica. Archived from the original on 2018-12-24. Retrieved 2018-12-24.
  9. ^ a b c d e f Liu, Shaochuang; Lu, P; Liu, D; Jin, P; Wang, W (2009-03-01). "Pinpointing the sources and measuring the lengths of the principal rivers of the world". Int. J. Digital Earth. 2 (1): 80–87. Bibcode:2009IJDE....2...80L. doi:10.1080/17538940902746082. S2CID 27548511. Archived from the original on 2018-12-23. Retrieved 2018-12-24.
  10. ^ a b c d J.C. Kammerer (1 September 2005). "Largest Rivers in the United States". US Geological Survey. Archived from the original on 13 May 2020. Retrieved 25 January 2015.
  11. ^ Roach, John (18 June 2007). "Amazon Longer Than Nile River, Scientists Say". National Geographic. Archived from the original on August 22, 2007. Retrieved 4 March 2015.
  12. ^ "Río de la Plata". Encyclopædia Britannica. Archived from the original on 9 May 2015. Retrieved 11 August 2010.
  13. ^ "Scientists pinpoint sources of four major international rivers". Xinhua News Agency. 22 August 2011. Archived from the original on December 30, 2013. Retrieved 8 September 2015.
  14. ^ "Brahmaputra River". Encyclopædia Britannica. Archived from the original on 2020-04-26. Retrieved 2017-04-11.
  15. ^ a b c d "Longest Rivers". Geoscience Australia. 15 May 2014. Archived from the original on 5 September 2015. Retrieved 9 February 2021.
  16. ^ Syvitski, James P. M., Vörösmarty, Charles J., Kettner, Albert J., Green, Pamela (2005). "Impact of Humans on the Flux of Terrestrial Sediment to the Global Coastal Ocean". Science. 308 (5720): 376–80. Bibcode:2005Sci...308..376S. doi:10.1126/science.1109454. PMID 15831750. S2CID 11382265. Archived from the original on 2006-09-19. Retrieved 2006-02-27.{{cite journal}}: CS1 maint: multiple names: authors list (link)
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  18. ^ Parua, Pranab Kumar (3 January 2010). The Ganga: water use in the Indian subcontinent. Springer. p. 272. ISBN 978-90-481-3102-0. Retrieved 17 May 2011.
  19. ^ "Ganges–Farakka". Archived from the original on 2018-03-10. Retrieved 2007-03-27.
  20. ^ Bossche, J.P. vanden; G. M. Bernacsek (1990). Source Book for the Inland Fishery Resources of Africa, Volume 1. Food and Agriculture Organization of the United Nations. p. 338. ISBN 978-92-5-102983-1. Archived from the original on 2023-11-10. Retrieved 2016-10-28.
  21. ^ a b "The Columbia River and Its Tributaries". USGS Volcanoes. Retrieved 2024-02-17.
  22. ^ Kammerer, J.C. (1987). "Largest Rivers in the United States". United States Geological Survey. Archived from the original on 2020-05-13. Retrieved 2006-07-15. {{cite journal}}: Cite journal requires |journal= (help)
  23. ^ "Uruguay River". Comisión Técnica Mixta de Salto Grande. Archived from the original on 8 June 2023. Retrieved 9 August 2023.
  24. ^ "Longest Rivers". Murray Darling Basin Authority. 24 November 2015. Archived from the original on 7 February 2019. Retrieved 4 February 2019.
  25. ^ a b "USGS Water Resources: About USGS Water Resources". water.usgs.gov. Retrieved 2024-02-17.
  26. ^ "USGS Gage #12472800 on the Columbia River below Priest Rapids Dam, WA (Water-Data Report 2013)" (PDF). National Water Information System. U.S. Geological Survey. Retrieved December 15, 2023.
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  29. ^ "Narmada Basin" (PDF). India WRIS. Archived (PDF) from the original on 29 November 2021. Retrieved 29 November 2021.
  30. ^ a b Bossche, J.P. vanden; G. M. Bernacsek (1990). Source Book for the Inland Fishery Resources of Africa, Volume 1. Food and Agriculture Organization of the United Nations. p. 333. ISBN 978-92-5-102983-1.
  31. ^ If the Meuse is considered a tributary, the Rhine basin is 218,300 km2.
  32. ^ Rogers, Aaron W. "White River - Encyclopedia of Arkansas". www.encyclopediaofarkansas.net. Archived from the original on 27 October 2018. Retrieved 27 October 2018.
  33. ^ Daily Telegraph, Monday 18 June 2007, page 18
  34. ^ a b "Amazon river flowed into the Pacific millions of years ago". mongabay.com. 24 October 2006. Archived from the original on 2017-12-12. Retrieved 2017-12-11.
  35. ^ Vaikmäe, R., Edmunds, W. M., and Manzano, M., (2001) "Weichselian palaeoclimate and palaeoenvironment in Europe: Background for palaeogroundwater formation Archived 2023-12-21 at the Wayback Machine", in "Palaeowaters in Coastal Europe: Evolution of Groundwater Since the Late Pleistocene" (W. M. Edmunds and C. J. Milne (eds)). London:The Geological Society. p. 177
  36. ^ Bridgland, D. R., and D'Olier, B. (1995) "The Pleistocene evolution of the Thames and Rhine drainage systems in the southern North Sea Basin (abstract) Archived 2022-06-27 at the Wayback Machine", Geological Society, London, Special Publications, v. 96, p. 27–45, in Lyell Collection. Retrieved 12 November 2015.

External links